New # command to toggle line numbers.

2 files changed, 43 insertions, 13 deletions

diff --git a/pw.1 b/pw.1
index 95be260..96925ed 100644
--- a/pw.1
+++ b/pw.1
@@ -373,6 +373,11 @@ opened position must be filled by a line of data from standard input. There is
 no way to reduce the size dynamically. Resizing is limited to the terminal
 height, if the height is known.
 
+.IP \fB#\fI
+Toggle the display of line numbers. In tail-referenced trigger mode,
+the lines are numbered from bottom to top.  In all other situations,
+top to bottom.
+
 .IP \fBCtrl-Z\fI
 Suspends
 .IR pw ,
@@ -402,13 +407,13 @@ and
 .BR Ctrl-N .
 
 .IP "\fB:w\fP \fIfilename\fP"
-Write the current contents of the display into the specified file.
+Write the currently displayed lines into the specified file.
 
 .IP "\fB:a\fP \fIfilename\fP"
-Append the current contents of the display into the specified file.
+Append the currently displayed lines into the specified file.
 
 .IP "\fB:!\fP \fIfilename\fP"
-Pipe the current contents of of the display into the specified command.
+Pipe the currently displayed lines into the specified command.
 
 .IP "\fB:g\fP \fIpattern\fP, \fB:v\fP \fIpattern\fP"
 Push a
diff --git a/pw.c b/pw.c
index 69898e1..9e2a32a 100644
--- a/pw.c
+++ b/pw.c
@@ -40,7 +40,8 @@ enum status_flags {
   stat_ttmode = 16, // tail trigger mode
   stat_trgrd = 32,  // triggered flag
   stat_grep = 64,   // grep mode
-  stat_force = 128  // force refresh even if clean
+  stat_force = 128, // force refresh even if clean
+  stat_lino = 256   // render line numbers
 };
 
 typedef struct grep {
@@ -247,10 +248,13 @@ static void clreol(int nl)
     putchar('\n');
 }
 
-static void drawline(const char *line, unsigned hpos, int columns)
+static void drawline(const char *line, unsigned hpos, int columns, int lineno)
 {
   size_t len = dslen(line);
 
+  if (lineno > 0)
+    columns -= printf("%3d ", lineno);
+
   if ((size_t) hpos <= len) {
     if (hpos) {
       line += hpos;
@@ -339,6 +343,8 @@ static void freebuf(char **buf, size_t size)
 static unsigned redraw(char **circbuf, int nlines, unsigned hpos, unsigned hist,
                        int columns, unsigned stat, char *cmd)
 {
+  int updln = 0;
+
   if ((stat & (stat_dirty | stat_susp)) == stat_dirty &&
       (stat & (stat_htmode | stat_trgrd)) != stat_htmode &&
       (stat & (stat_ttmode | stat_trgrd)) != stat_ttmode)
@@ -351,21 +357,36 @@ static unsigned redraw(char **circbuf, int nlines, unsigned hpos, unsigned hist,
     memmove(snaplines + 1, snaplines, sizeof *snaplines * (snhistsize - 1));
     snapshot[0] = calloc(sizeof *snapshot[0], nlines);
     snaplines[0] = nlines;
-    printf("\r\033[%dA", nlines);
-    for (int i = 0; i < nlines; i++) {
+    updln = 1;
+    for (int i = 0; i < nlines; i++)
       snapshot[0][i] = dsref(circbuf[i]);
-      drawline(snapshot[hist][i], hpos, columns);
-    }
     stat &= ~(stat_dirty | stat_trgrd);
+    updln = 1;
   } else if ((stat & stat_force)) {
-    printf("\r\033[%dA", snaplines[hist]);
-    for (int i = 0; i < snaplines[hist]; i++)
-      drawline(snapshot[hist][i], hpos, columns);
     stat &= ~stat_force;
+    updln = 1;
+  }
+
+  if (updln) {
+    printf("\r\033[%dA", snaplines[hist]);
+    if ((stat & stat_lino) == 0) {
+      for (int i = 0; i < snaplines[hist]; i++)
+        drawline(snapshot[hist][i], hpos, columns, -1);
+    } else {
+      int start = 1, step = 1;
+      if (stat & stat_htmode) {
+        start = snaplines[hist];
+        step = -1;
+      }
+      for (int i = 0, l = start; i < snaplines[hist]; i++, l += step)
+        drawline(snapshot[hist][i], hpos, columns, l);
+    }
   } else {
     clrline();
   }
+
   drawstatus(hist, columns, stat, cmd);
+
   return stat;
 }
 
@@ -789,7 +810,7 @@ int main(int argc, char **argv)
               snapshot[0] = resizebuf(snapshot[0], snaplines[0], snaplines[0] + 1);
               snapshot[0][snaplines[0]++] = dsref(line);
               clrline();
-              drawline(line, hpos, columns);
+              drawline(line, hpos, columns, -1);
               drawstatus(hist, columns, stat, curcmd);
             }
           }
@@ -1001,6 +1022,10 @@ int main(int argc, char **argv)
               }
             }
             break;
+          case '#':
+            stat ^= stat_lino;
+            stat |= stat_force;
+            break;
           case '0':
             if (cmdcount == UINT_MAX) {
               hpos = 0;